Multiple Choice
Identify the
choice that best completes the statement or answers the question.
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1.
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To determine the age of fairly recent fossils and organic artifacts, it is
possible to analyze the amounts of the isotopes 14C and 14N, because over time
the 14C—which originated in the atmosphere—breaks down into 14N.
What net change occurred for this to happen?
A) | The 14C lost an electron. | B) | The 14C lost a
proton. | C) | The 14C gained a proton. | D) | The 14C gained a
neutron. |
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2.
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In blood, carbon dioxide and water form carbonic acid. What affect will a
reduced respiratory rate have on the pH of the blood?
A) | The blood pH will remain constant since equal amounts of hydrogen and hydroxyl ions
are formed. | B) | The intake of more oxygen will reduce the pH of the blood due to oxygen’s
ability to bind with hydrogen. | C) | The presence of more carbon dioxide will result
in a decrease in the pH of the blood due to the formation of carbonic acid. | D) | The water changes
its pH because of the ions produced when carbon dioxide is trapped in the
lungs. |
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3.
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From the table below, it is apparent that Bond | Energy (kcal/mol) | Bond | Energy (kcal/mol) | H—H | 104 | P—O | 100 | H—O | 110 | N—O | 53 | C—H | 99 | S—H | 81 | C—O | 84 | C=C | 146 | C—C | 83 | C=N | 147 | C—N | 70 | P=O | 120 | C—S | 62 | C=O | 170 | S—S | 51 | C=C | 195 | | | | |
A) | triple bonds are stronger than double bonds; double bonds are stronger than single
bonds | B) | triple bonds are weaker than double bonds; double bonds are weaker than single
bonds | C) | carbon bonds are stronger than other bonds; hydrogen bonds are always
weakest | D) | carbon is unable to bond with itself |
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4.
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The subatomic particle of an atom that carries no charge is a (an)
A) | electron | B) | proton | C) | neutron | D) | ion |
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5.
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In the water molecule
A) | the oxygen molecule is more electronegative than the hydrogen | B) | the oxygen atom has
an overall negative charge with the hydrogen atoms have an overall positive
charge | C) | unequal sharing of electrons results in a polar molecule | D) | all of the choices
are correct |
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6.
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As a solid, water (ice) floats. This means that
A) | organisms in ponds, lakes, and reservoirs cannot photosynthesize under the
water | B) | covalent bonding occurred between water molecules | C) | there is more space
between the molecules in ice than in liquid water | D) | All of the choices are
correct |
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7.
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“CHNOPs” is an acronym for
A) | carbon based life forms | B) | origin of life | C) | the elements that
compose living organisms | D) | covalent bonds that form between hydrogen and
other elements |
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8.
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Organic molecules are those that contain at least
A) | carbon | B) | carbon and oxygen | C) | carbon and
hydrogen | D) | carbon, oxygen, and hydrogen | E) | carbon and
nitrogen |
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9.
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What term is based on the Greek root words for "equal" and
"part"?
A) | Isotope | B) | Isomer | C) | Homomolecules | D) | Hydrophilic |
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10.
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Which carbohydrate is used in the liver for energy storage?
A) | Starch | B) | Cellulose | C) | Glycerol | D) | Glycogen |
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11.
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Which of the following pair of words best completes the statement:
A(n)_____
fat will have _____ bonds between the carbon atoms of the fatty acid and will be a ____ at room
temperature.
A) | Saturated; single; liquid | B) | Unsaturated; single; solid | C) | Saturated; double;,
liquid | D) | Unsaturated; double; liquid |
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12.
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The alpha helix and beta sheet are found at which level of protein
organization?
A) | Primary structure | B) | Secondary structure | C) | Tertiary
structure | D) | Quaternary structure |
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13.
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The breakfast dishes have dried yellow egg on them when you return in the
evening. The dried yellow egg remains after you dunk the dirty dishes in water. After soaking awhile,
the complex of various egg yolk molecules easily "washes off." What has happened?
A) | Soaking in water eventually resulted in hydrolysis reactions where water broke these
bonds. | B) | The egg monomers were fused to become one polymer, which was easily dissolved by
water back into monomers. | C) | The presence or absence of water changes the
molecules from hydrophilic to hydrophobic respectively. | D) | The addition of
water converted organic molecules into inorganic molecules. |
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14.
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Which statement is true about RNA?
A) | It contains adenine paired to thymine. | B) | One of the bases from DNA is replaced by
uracil. | C) | Its nucleotides contain twice as many phosphate groups as DNA's
nucleotides. | D) | It is a double-stranded molecule. |
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15.
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A new phosphorous based form of life has been discovered on Jupiter. Scientists
expect the phosphorous based life forms to be less diverse than carbon based life forms
because
A) | phosphorous binds to hydrogen | B) | carbon can form single and double bonds with
itself and other elements | C) | organic molecules always contain ionic
bonds | D) | phosphorous is often an isotope |
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Essay
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1.
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Water has unique properties which have resulted in it being essential to life.
Describe three of the characteristics of water and discuss how each of these characteristics would
aid in the survival of living organisms.
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